MR features of physiologic and benign conditions of the ovary

CT review of ovarian fibrothecoma

Objective:

The aim of this study was to investigate the CT imaging characteristics of ovarian fibrothecoma which may aid in the differentiation from early stage epithelial tumours.

Methods:

Comparison of 36 patients (41 lesions) with pathologically proven ovarian fibrothecoma tumours and 36 (52 lesions) serous papillary carcinomas (SPCs) lesions. We noted their laterality, size, density, calcifications, Hounsfield units (HUs) and introduced a novel HU comparison technique with the psoas muscle or the uterus. Patients’ clinical findings such as ascites, pleural effusion, carbohydrate antigen-125 levels, and lymphadenopathy findings were also included.

Results:

Average age was 67.8 and 66 across the fibrothecoma and SPC cohort respectively. Fibrothecoma tumours had diameters ranging from 24 to 207 mm (Median: 94 mm). 80.6% of the fibrothecoma cohort had ascites which was comparable to the 72.2% in the SPC cohort. 70.7% of fibrothecoma tumour favour a purely to predominantly solid structural configuration (p < 0.001). The average HU value for the fibrothecoma solid component was 44 ± 11.7 contrasting the SPC HU value of 66.8 ± 15. The psoas:tumour mass ratio demonstrated a median of 0.7, whereas SPCs shows a median of 1.1 (p < 0.001).

Conclusion:

Suspicion of ovarian fibrothecoma should be considered through interrogation of their structural density configuration, low psoas to mass HU ratio and a presence of ascites.

Advances in knowledge:

CT imaging can be a useful tool in diagnosing fibrothecoma tumours and subsequently reducing oncogynaecological tertiary centre referrals, financial burden and patient operative morbidity and mortality.

All that glitters are not gold: holds true in female adnexal lesions

Background

Adnexal mass lesions are commonly encountered pathologies that creates diagnostic challenges for radiologist. Diffusion weighted imaging is a vital tool in the radiologist armamentarium for improving the diagnostic accuracy of adnexal lesions other than routine spine echo sequences.

Main body

Functional information about the lesion regarding the mobility of the water molecules in its tissue is assessed by diffusion weighted imaging. In addition to the solid malignant neoplasm, normal blood, fat, necrosis and pus also shows restricted diffusion.

Conclusion

All the lesion that shows restriction in the DWI are not malignant, but converse is mostly true. Knowledge regarding the non-malignant lesion in the ovary that shows restricted diffusion will give a clue in diagnosis, management and treatment of the adnexal lesions.

Diffusivity mapping of the ovaries: Variability of apparent diffusion and kurtosis variables over the menstrual cycle and influence of oral contraceptives

PURPOSE

We aimed to investigate whether quantitative diffusivity variables of healthy ovaries vary during the menstrual cycle and to evaluate alterations in women using oral contraceptives (OC).

METHODS

This prospective study (S-339/2016) included 30 healthy female volunteers, with (n = 15) and without (n = 15) intake of OC between 07/2017 and 09/2019. Participants underwent 3T diffusion-weighted MRI (b-values 0-2000 s/mm²) three times during a menstrual cycle (T1 = day 1-5; T2 = day 7-12; T3 = day 19-24). Both ovaries were manually three-dimensionally segmented on b = 1500 s/mm²; apparent diffusion coefficient (ADC) calculation and kurtosis fitting (D_app, K_app) were performed. Differences in ADC, D_app and K_app between time points and groups were compared using repeated measures ANOVA and t-test after Shapiro-Wilk and Brown-Forsythe test for normality and equal variance.

RESULTS

In women with a natural menstrual cycle, ADC and kurtosis variables showed significant changes in ovaries with the dominant follicle between T1 vs T2 and T1 vs T3, whilst no differences were observed between T2 vs T3: ADC ± SD for T1 1.524 ± 0.160, T2 1.737 ± 0.160, and T3 1.747 ± 0.241 μm²/ms (p = 0.01 T2 vs T1; p = 1.0 T2 vs T3, p = 0.003 T3 vs T1); D_app ± SD for T1 2.018 ± 0.140, T2 2.272 ± 0.189, and T3 2.230 ± 0.256 μm²/ms (p = 0.003 T2 vs T1, p = 1.0 T2 vs T3, p = 0.02 T3 vs T1); K_app ± SD for T1 0.614 ± 0.0339, T2 0.546 ± 0.0637, and T3 0.529 ± 0.0567 (p < 0.001 T2 vs T1, p = 0.86 T2 vs T3, p < 0.001 T3 vs T1). No significant differences were found in the contralateral ovaries or in females taking OC.

CONCLUSION

Physiological cycle-dependent changes in quantitative diffusivity variables of ovaries should be considered especially when interpreting radiomics analyses in reproductive women.

Pearls and Pitfalls in Imaging of Pelvic Adnexal Torsion: Seven Tips to Tell It's Twisted

Pelvic adnexal torsion is a collective term referring to twisting of an ovary, fallopian tube, or paraovarian cyst on its axis with varying degrees of vascular compromise. Although it is the fifth most common gynecologic emergency, the diagnosis is challenging and often missed due to symptoms, physical examination findings, and imaging features that are nonspecific. Delay in salvage surgery may lead to ovarian or tubal loss, dysfunction, and infertility. The tips shared herein are based on the authors' observations of key clinical and imaging features of torsion, with the intent of heightening radiologists' index of suspicion and diagnostic accuracy in a clear and memorable fashion. Clinically, severe acute pain with a known adnexal mass or of severity to elicit nausea or vomiting should raise concern. At imaging, features of ovarian edema are key to the diagnosis, including asymmetric ovarian enlargement, peripheralized follicles, adjacent free fluid, and foci of stromal hemorrhage. The converse finding of symmetric nonenlarged ovaries in a normal location with any imaging modality has a high negative predictive value for torsion, obviating the need for additional imaging. The whirlpool sign (twisted vascular pedicle), abnormal ovarian location, and uterine tilting are additional key imaging manifestations. The presence of color Doppler flow or contrast enhancement only suggests that an ovary is still viable and should not be used to exclude the diagnosis of torsion. In cases of isolated tubal or paraovarian cyst torsion, the ovaries may appear normal; therefore, recognition of this entity along with appreciation of several key imaging findings may assist with this difficult diagnosis. An invited commentary by Dighe is available online. Online supplemental material is available for this article. ^©RSNA, 2021.

Comparison of image features and diagnostic value of color Doppler ultrasound and two-dimensional ultrasound in the diagnosis of ovarian sex cord-stromal tumors

Clinical value of color Doppler ultrasound and two-dimensional ultrasound in the diagnosis of ovarian sex cord-stromal tumors (OSCSTs) were explored. A total of 91 patients with positive OSCSTs admitted to Sichuan Provincial Hospital for Women and Children from May 2014 to June 2018 were selected as research objects. There were 48 patients diagnosed by color Doppler ultrasound technology as the color Doppler group and 43 patients diagnosed by two-dimensional ultrasound technology as the two-dimensional ultrasound group. Results of ultrasound images in the two groups were compared, and the diagnostic value of two ultrasound techniques combined with detection of CA125 and CA199 for OSCSTs was compared. The real internal echo of color Doppler ultrasound was significantly higher than that of two-dimensional ultrasound (P<0.05). The blood flow signal of color Doppler ultrasound was significantly higher than that of two-dimensional ultrasound (P<0.05). The diagnostic sensitivity and diagnostic coincidence rate of color Doppler ultrasound for lymph node metastasis of OSCSTs were significantly higher than those of two-dimensional ultrasound (P<0.05). Color Doppler ultrasound combined with CA125 and CA199 detection has higher accuracy than two-dimensional ultrasound combination. In conclusion, both color Doppler ultrasound and two-dimensional ultrasound are used to observe OSCSTs for early diagnosis, but the sensitivity and diagnostic coincidence rate of color Doppler ultrasound for clinical diagnosis of OSCSTs are higher than those of two-dimensional ultrasound, so color Doppler ultrasound has higher diagnostic value in OSCSTs.

Ovarian solid tumors: MR imaging features with radiologic-pathologic correlation

Ovarian solid tumors have variable histological types including benign and malignant tumors. In addition, non-neoplastic lesions sometimes show a tumor-like appearance. It is important to differentiate benign from malignant tumors. In general, low signal intensity (SI) on T2-weighted imaging (T2WI), low SI on diffusion-weighted imaging (DWI), and gradual increased pattern on dynamic contrast-enhanced magnetic resonance (MR) imaging are known to be suggestive of a benign tumor. Conversely, there are some cases in which these rules do not apply. We should, therefore, strive for a greater understanding of these exceptional cases. Several tumors show characteristic findings on MR imaging reflecting pathologic features, which leads to the correct diagnosis. Additionally, MR imaging provides important information other than the nature of tumors, such as secondary uterine changes. Furthermore, clinical findings and laboratory examination data also help in determining the correct diagnosis.

Investigation of clinical utility of contrast-enhanced MRI in the diagnosis of ectopic pregnancy

AIM

To investigate whether contrast-enhanced (CE)-magnetic resonance imaging (MRI) improves identification of implantation site of ectopic pregnancy.

MATERIALS AND METHODS

This retrospective study enrolled 63 patients in whom implantation sites had been confirmed at histopathology. Two expert radiologists for gynaecological imaging and two inexpert radiologists independently reviewed non-CE MRI and a combination of non-CE and CE-MRI (non-CE+CE-MRI), then determined implantation site with a confidence level. The following MRI features were also evaluated: extrauterine gestational sac (GS)-like structure (shape, signal intensities at T1-weighted imaging [WI], T2WI, and diffusion-weighted imaging [DWI], presence of the three rings appearance, and distinct low intensity areas at T2WI, presence of tree or dot-like components, degree of contrast enhancement), fallopian tube (dilatation, dilatation with haematoma, degree of contrast enhancement, enhanced components within the tube), and ascites. These findings were compared for non-CE and non-CE+CE-MRI data, and for expert and inexpert groups.

RESULTS

The expert group identified implantation sites correctly in 58/63 (92%) cases for non-CE and non-CE+CE-MRI. In the inexpert group, the correct identification was improved from 54/63 (86%) using non-CE MRI to 58/63 (92%) using non-CE+CE-MRI, but was not significant (p=0.29). In comparison between non-CE and non-CE+CE-MRI, dilation of the fallopian tubes was observed more frequently (p=0.004) and the confidence level was elevated significantly in the non-CE+CE-MRI (p<0.0001) in the inexpert group. Intergroup comparison revealed that confidence level was significantly higher in the expert group than in the inexpert group using non-CE MRI (p<0.0001), although the difference was not significant at non-CE+CE MRI (p=0.49).

CONCLUSION

CE-MRI did not significantly improve correct identification of ectopic pregnancy implantation sites, although the addition of contrast enhancement did enable inexpert radiologists to diagnose confidently.

Benign ovarian lesions with restricted diffusion

Developments in magnetic resonance imaging have expanded its role in the assessment of the female pelvis, including the diagnosis of ovarian lesions. In this setting, diffusion-weighted imaging has proven its diagnostic value, which is particularly important in differentiating between benign and malignant ovarian tumors. In general, the latter show restricted diffusion, whereas the former do not. Exceptions include teratomas, endometriomas, hemorrhagic cysts, ovarian abscesses, ovarian infarction, and some benign stromal tumors. The aim of this review is to draw attention to benign ovarian lesions with restricted diffusion, with a special focus on diffusion-weighted imaging pearls and pitfalls.

The value of MR-detectable ipsilateral ovaries in characterizing the origin and malignancy of an adnexal tumors

OBJECTIVE

To investigate the magnetic resonance (MR) imaging morphological relationship between adnexal tumors and the ipsilateral ovaries to characterize the origin and malignancy of tumors.

MATERIAL AND METHODS

Clinical and MR imaging data of 496 adnexal tumors confirmed by histology (ovary tumors, n = 400, non-ovarian tumors, n = 96; benign tumors, n = 183, borderline tumors, n = 120, and malignant tumors, n = 193) were retrospectively analyzed. The presence and shape of the ipsilateral ovaries within the context of adnexal tumors of different origins, malignancies and configurations were evaluated. The relationships between the presence of the ipsilateral ovary and patient age, menstrual status and tumor size were also analyzed.

RESULT

The ipsilateral ovary was detected on MRI in 23% (90/400) of ovarian tumors and in 45% (43/96) of non-ovarian tumors (p < 0.001). A normal ovoid morphology of the ipsilateral ovary was found in only 7% (26/400) of ovarian tumors and in 26% (25/96) of non-ovarian tumors (p < 0.001). The ipsilateral ovary was detectable in 38% (69/183) of benign tumors, 35% (42/120) of borderline tumors, and 11% (22/193) of malignant tumors (p <  0.001); in 24% (24/101) of cystic tumors, 27% (49/179) of mixed cystic-solid tumors and 28% (60/216) of solid tumors (p = 0.737); and in 40% (120/303) of adnexal tumors in premenopausal patients and 7% (13/193) of adnexal tumors in postmenopausal patients (p < 0.001).

CONCLUSION

Detection of the ipsilateral ovary contributes to the localization and characterization of adnexal tumors. The ipsilateral ovary can be detected more frequently in non-ovarian tumors and in benign or borderline ovarian tumors.

Magnetic resonance imaging of common, uncommon, and rare implantation sites in ectopic pregnancy

OBJECTIVE

To review the MRI appearances of tubal and non-tubal implantation sites in ectopic pregnancy.

CONCLUSION

Transvaginal ultrasound is the primary imaging modality in ectopic pregnancy and MRI is used as a problem-solving tool in selected indications as detailed in the article. MRI features of tubal, interstitial, cervical, cesarean scar, cornual, ovarian, abdominal, and heterotopic pregnancies are provided to familiarize the radiologists with their appearances thereby assisting them in making early and accurate diagnosis.

Pitfalls of diffusion-weighted imaging of the female pelvis

Diffusion-weighted imaging (DWI) is widely used in protocols for magnetic resonance imaging (MRI) of the female pelvis. It provides functional and structural information about biological tissues, without the use of ionizing radiation or intravenous administration of contrast medium. High signal intensity on DWI with simultaneous low signal intensity on apparent diffusion coefficient maps is usually associated with malignancy. However, that pattern can also be seen in many benign lesions, a fact that should be recognized by radiologists. Correlating DWI findings with those of conventional (T1- and T2-weighted) MRI sequences and those of contrast-enhanced MRI sequences is mandatory in order to avoid potential pitfalls. The aim of this review article is the description of the most relevant physiological and benign pathological conditions of the female pelvis that can show restricted diffusion on DWI.

Multimodality imaging findings of massive ovarian edema in children

BACKGROUND

Massive ovarian edema is a rare benign condition that predominantly affects childbearing women as well as preadolescent girls. It is thought to result from intermittent or partial torsion of the ovary compromising the venous and lymphatic drainage but with preserved arterial supply. The clinical features of massive ovarian edema are nonspecific and can simulate tumors, leading to unnecessary oophorectomy.

OBJECTIVE

To demonstrate imaging features that should alert radiologists to consider the diagnosis of massive ovarian edema preoperatively so that fertility-sparing surgery may be considered.

MATERIALS AND METHODS

We identified five girls diagnosed with massive ovarian edema at pathology. Presenting symptoms, sidedness, imaging appearance, preoperative diagnosis, and operative and histopathological findings were reviewed.

RESULTS

Age range was 9.6-14.3 years (mean age: 12.5 years). Common imaging findings included ovarian enlargement with edema of the stroma, peripherally placed follicles, isointense signal on T1-W MRI and markedly hyperintense signal on T2-W MRI, preservation of color Doppler flow by US, and CT Hounsfield units below 40. The uterus was deviated to the affected side in all patients. Two of the five patients had small to moderate amounts of free pelvic fluid. Mean ovarian volume on imaging was 560 mL (range: 108-1,361 mL).

CONCLUSION

While the clinical presentation of massive ovarian edema is nonspecific, an enlarged ovary with stromal edema, peripherally placed follicles and preservation of blood flow may be suggestive and wedge biopsy should be considered intraoperatively to avoid unnecessary removal of the ovary.

MR Imaging for Incidental Adnexal Mass Characterization

Incidentally detected adnexal masses are common, and the overwhelming majority of them are benign. As many of these adnexal masses are considered indeterminate at CT or US, a large number of benign oophorectomies occur. Of the malignant adnexal masses, high-grade primary ovarian neoplasms with fast doubling times and early dissemination are the most common. Due to their aggressive behavior, diagnosis of malignancy by interval growth on surveillance imaging represents an undesirable option. Immediate MR characterization allows for a decreased rate of benign oophorectomies and expedited triage of patients to definitive treatment when malignancy is suspected.

Radiological appearances of corpus luteum cysts and their imaging mimics

PURPOSE

To review the radiological appearances of corpus luteum cysts and their imaging mimics.

CONCLUSION

Corpus luteum cysts are normal post-ovulatory structures seen in the ovaries through the second half of the menstrual cycle and the first trimester of pregnancy. The typical appearance, across all modalities, is of a 1- to 3-cm cyst with a thick crenulated vascularized wall. Occasionally, similar imaging findings may be seen with endometrioma, ectopic pregnancy, tuboovarian abscess, red degeneration of a fibroid, and ovarian neoplasia. In most cases, imaging findings are distinctive and allow for a confident and accurate diagnosis that provides reassurance for patients and referring physicians and avoids costly unnecessary follow-up.

Magnetic resonance imaging features of ovarian fibroma, fibrothecoma, and thecoma

OBJECTIVE

To retrospectively evaluate the conventional and functional (diffusion- or perfusion-weighted) magnetic resonance (MR) imaging features of ovarian fibroma, fibrothecoma, and thecoma.

MATERIALS AND METHODS

Histologically proven ovarian fibromas (n = 19), fibrothecomas (n = 7), and thecomas (n = 2) were reviewed (26 patients). The morphologic and signal intensity (SI) characteristics on conventional MR imaging (n = 28, all cases) were analyzed. The b 1000 signal intensity on diffusion-weighted image (DWI) (n = 22) and the time-to-signal intensity curve on perfusion-weighted image (PWI) (n = 7) were also analyzed. The presence and shape of the ipsilateral ovarian tissue surrounding the lesions were evaluated on T2-weighted image.

RESULTS

Twenty-two cases (79%) were predominantly solid tumor. Majority of the detected lesions exhibited the characteristic homogeneous low SI on T1- (24/28, 86%) and T2- (19/28, 68%) weighted image. Conversely, a number of lesions exhibited high SI (9/28, 32%) on T2-weighted image. Most lesions presented with a detectable ipsilateral ovary on T2-weighted image (24/28, 86%). Tumors larger than 6 cm more likely showed atypical morphology (mixed solid and cystic, cystic), atypical SI (high on T1- and T2-weighted image), and large amount ascites. Larger tumor group (>6 cm) was more likely diagnosed as fibrothecoma or thecoma than fibroma by pathology. On DWI, 16 lesions showed low b 1000 signal intensity (16/22, 73%). On PWI, all lesions showed curve type 1 or 2 (7/7, 100%), which tends to characterize benign lesions. All (16/16, 100%) pre-menopausal women had a detectable ipsilateral ovary, and six (60%) out of 10 post-menopausal women had a detectable ipsilateral ovary (p < 0.05).

CONCLUSIONS

Combining conventional morphologic and signal intensity characteristics with the findings from DWI or PWI might help differentiate ovarian fibroma, fibrothecoma, and thecoma from ovarian malignancy, although further prospective larger scale study using DWI and PWI is needed.

MRI diagnosis of ovarian fibrothecomas: tumour appearances and oestrogenic effect features

OBJECTIVE

To study MRI diagnosis of ovarian fibrothecomas.

METHODS

MRI appearances of 27 ovarian fibrothecomas 26 female patients confirmed by surgical pathology were retrospectively reviewed and correlated with clinical and histological findings.

RESULTS

Most patients were post-menopausal females 73.1% (19/26) of cases. 38.5% (10/26) of patients showed an elevated serum carbohydrate antigen 125 (CA-125) level (>35 U ml(-1)). On MR T2 weighted imaging, 3 distinct features were revealed. (1) Homogeneous hypointense masses in 25.9% (7/27) cases. (2) Heterogeneous tumours with mostly isointense and few patchy hyperintense areas in 51.9% (14/27) cases. (3) Heterogeneous tumours with predominantly hyperintense and few isointense parts in 22.2% (6/27) cases. On T1 weighted imaging, all the fibrothecomas turned out to be homogeneous masses except six cystic degeneration cases. After contrast, 70.4% (19/27) tumours showed homogeneous mild enhancement in all phases. Beyond the tumours, endometrial abnormality and uterus enlargement were found in 38.5% (10/26) and 15.4% (4/26) patients, respectively. Ascites were seen in 53.8% (14/26) patients. There was a statistically significant difference among the 3 T2 weighted image features (F = 7.024; p = 0.003) in terms of the size of fibrothecomas. The cystic tumours also had the tendency to show the ascite condition (p = 0.002) as well as elevated serum CA-125 levels (p = 0.014). Vimentin was positively stained in 10 (76.9%) of 13 cases who underwent the immunohistochemical analysis.

CONCLUSION

MRI has the superiority to show the distinct appearances of tumours as well as their functional features according to oestrogenic effect.

ADVANCES IN KNOWLEDGE

This study describes the unique features of fibrothecomas on MRI on a relatively large series of patients with tumours and the indirect oestrogenic effect findings.

Diffusion-weighted imaging of ovarian torsion: usefulness of apparent diffusion coefficient (ADC) values for the detection of hemorrhagic infarction

PURPOSE

We undertook this study to evaluate the need for diffusion-weighted (DW) magnetic resonance (MR) imaging in detecting hemorrhagic infarction following ovarian torsion.

METHODS

The study included 14 consecutive patients aged 12 to 74 years (average age, 36 years) with surgical confirmation of ovarian torsion who underwent 1.5-tesla MR imaging. Pathologically, hemorrhagic infarction was found in 7 patients. We retrospectively reviewed signal intensity on T1-, T2-, and diffusion-weighted images and apparent diffusion coefficients (ADCs) in swollen ovarian stroma.

RESULTS

Fallopian tube thickening was seen in all patients. In patients with ovarian cystic lesion, maximum cyst wall thickness was significantly higher in patients with hemorrhagic infarction (mean, 13.5 ± 4.1 mm) than those without (mean, 5.0 ± 1.0 mm) (P < .05). Signal intensity did not differ significantly on T1-weighted, T2-weighted, and DW images between patients with and without hemorrhagic infarction. ADCs were significantly lower in patients with hemorrhagic infarction (1.20 ± 0.50 [× 10(-3) mm(2)/s]) than those without (2.04 ± 0.26 [× 10(-3) mm(2)/s]) (P < .01). With an ADC threshold of 1.80 [× 10(-3) mm(2)/s], sensitivity for hemorrhagic infarction was 0.88 (7 of 8), and specificity was 1.00 (6 of 6).

CONCLUSION

ADC measurements were useful for detecting hemorrhagic infarction in patients with ovarian torsion.

MR imaging findings of ectopic pregnancy: a pictorial review

Because of its lack of ionizing radiation and excellent soft-tissue contrast, magnetic resonance (MR) imaging is being increasingly used in the evaluation of acute abdominal pain in the pregnant patient. Roughly 2% of all pregnancies are ectopic. Although ectopic pregnancy is usually diagnosed on the basis of a combination of clinical, laboratory, and ultrasonographic findings, it occasionally is initially identified at MR imaging. Thus, it is imperative that the radiologist should be familiar with the variable appearance of ectopic pregnancy at MR imaging and should evaluate for ectopic pregnancy at any time when (a) a patient has positive results of a pregnancy test and (b) an intrauterine pregnancy is not definitively seen. Because of potential issues of fetal safety, a conservative approach should be used for MR imaging in pregnancy. An MR imaging protocol for the evaluation of possible appendicitis in pregnant women is detailed. Specific findings that can aid in the diagnosis of ectopic pregnancy are the lack of an intrauterine pregnancy, isolated hemoperitoneum, tubal masses, hematosalpinx, and interstitial masses. In the differential diagnosis of acute abdominal pain in pregnancy, consideration should be given to the more unusual forms of ectopic pregnancy, such as angular pregnancy, cornual pregnancy, and abdominal pregnancy. Potential mimics of ectopic pregnancy include placental abnormalities, ovarian neoplasms, and corpus luteum cysts.

Imaging features and pathologic characteristics of ovarian thecoma

OBJECTIVE

To analyze the imaging findings of ovarian thecoma and to better understand the tumor features based on aspect of computed tomography and magnetic resonance images.

METHODS

Nineteen ovarian thecomas confirmed by histopathologic examination were analyzed retrospectively. Image characteristics were analyzed and compared with those of the pathologic features.

RESULTS

The mean diameter of tumors was 9.6 cm. The masses were well defined (n = 17) or ill defined (n = 2) and appeared solid with cystic areas (n = 11), entirely solid (n = 4), or cystic with solid components (n = 4). On T2-weighted/spectral adiabatic inversion recovery (T2WI/SPAIR) images, 12 cases appeared isointense or slightly hyperintense. Of the 12 cases, 8 had patchy hypersignal areas. On computed tomographic images, 7 cases showed hypodensity or isodensity. All tumors exhibited mild enhancement. On pathologic examination, the tumor was composed of spindle cells with a moderate amount of cytoplasm.

CONCLUSION

Imaging manifestations of ovarian thecoma are various and nonspecific. However, a large, well-defined mildly enhanced solid mass with cystic areas and especially isointense or slightly hyperintense on T2WI/SPAIR sequence in pelvic cavity may suggest the diagnosis of ovarian thecoma.

Benign and Suspicious Ovarian Masses-MR Imaging Criteria for Characterization: Pictorial Review

Ovarian masses present a special diagnostic challenge when imaging findings cannot be categorized into benign or malignant pathology. Ultrasonography (US), Computed Tomography (CT), and Magnetic Resonance Imaging (MRI) are currently used to evaluate ovarian tumors. US is the first-line imaging investigation for suspected adnexal masses. Color Doppler US helps the diagnosis identifying vascularized components within the mass. CT is commonly performed in preoperative evaluation of a suspected ovarian malignancy, but it exposes patients to radiation. When US findings are nondiagnostic or equivocal, MRI can be a valuable problem solving tool, useful to give also surgical planning information. MRI is well known to provide accurate information about hemorrhage, fat, and collagen. It is able to identify different types of tissue contained in pelvic masses, distinguishing benign from malignant ovarian tumors. The knowledge of clinical syndromes and MRI features of these conditions is crucial in establishing an accurate diagnosis and determining appropriate treatment. The purpose of this paper is to illustrate MRI findings in neoplastic and non-neoplastic ovarian masses, which were assessed into three groups: cystic, solid, and solid/cystic lesions. MRI criteria for the correct diagnosis and characteristics for differentiating benign from malignant conditions are shown in this paper.

Magnetic resonance manifestations of hyperreactio luteinalis

OBJECTIVE

Hyperreactio luteinalis (HL) is a rare benign physiological ovarian enlargement associated with gestational trophoblastic disease or pregnancy, and may mimic neoplasm. We evaluated magnetic resonance findings of HL to distinguish from neoplasm by using diffusion-weighted imaging with apparent diffusion coefficient (ADC) measurement.

METHODS

Magnetic resonance manifestations of 15 cases of HL in 8 women (mean age, 32 years) were retrospectively evaluated. Diffusion-weighted imaging (b = 0 and 800 seconds/mm²) was obtained in 11 cases of HL, and ADC was compared with that in solid portions of 18 ovarian cancers.

RESULTS

All cases of HL appeared as multilocular cystic masses with septations mimicking mucinous cystic tumors. Intervening ovarian stroma exhibited hyperintensity on diffusion-weighted imaging. The ADC in ovarian stroma in HL was significantly higher than that in solid portions of ovarian cancers.

CONCLUSION

Ovarian stroma in HL may mimic solid tumorous components in mucinous tumors; however, high ADC reflecting edematous, luteinized stroma may be helpful for the diagnosis of HL.

MR findings of ruptured endometrial cyst: comparison with tubo-ovarian abscess

OBJECTIVE

To evaluate the MR findings of ruptured endometrial cyst, focusing on the differentiation from tubo-ovarian abscess (TOA).

PATIENTS AND METHODS

We reviewed the records of 21 patients who underwent preoperative MR examinations for TOAs (n=15) or ruptured endometrial cysts (n=6). We evaluated the presence of hyper-intense ascites and hyper-intense peritoneum in T1-weighted sequences, strong enhancement of the peritoneum, hyper-intense content and hyper-intense rim of the ovarian lesion in T1-weighted sequences, and strong wall enhancement of the ovarian lesion. χ2 test was used to assess the relationship between TOA cases versus cases with ruptured endometrial cysts, and the three MR peritoneal findings. We evaluated the relationship between TOA versus non-infected endometrial cysts, and the ovarian MR peritoneal findings, too.

RESULTS

Hyper-intense ascites was found in all of the patients with ruptured endometrial cyst and none with TOA (p<0.0001). Hyper-intense peritoneum was observed in only TOAs cases (4 of 8). Strong peritoneal enhancement was seen in 3 of the 3 patients with ruptured endometrial cyst and 7 of the 13 patients with TOA (p=0.1366). Hyper-intense content of the ovarian lesion was seen more often in the non-infected endometrial cysts than in the TOAs (p=0.001607), while hyper-intense rim was more frequent in TOAs (p=0.000402). Strong wall enhancement was observed only in TOAs (11 of 15) (p=0.001355).

CONCLUSIONS

MR images are useful to differentiate ruptured endometrial cyst from TOA.

Role of multidetector computed tomography (MDCT) in patients with ovarian masses

Objective:

To evaluate the diagnostic accuracy of multidetector 64-slice computed tomography (MDCT) in the diagnosis and differentiation of benign and malignant ovarian masses using histopathology and surgical findings as the gold standard.

Material and methods:

This study was conducted in Aga Khan University Hospital, Karachi, Pakistan. Data was reviewed retrospectively from 1 November 2008 to 12 December 2009. One hundred patients found to have ovarian masses on CT scan were included in the study. CT scan was performed in all these patients after administration of oral and IV contrast. Ovarian masses were classified as benign and malignant on scan findings. Imaging findings were compared with histopathologic results and surgical findings. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and diagnostic accuracy of MDCT were calculated.

Results:

MDCT was found to have 97% sensitivity, 91% specificity, and an accuracy of 96% in the differentiation of benign and malignant ovarian masses, while PPV and NPV were 97% and 91%, respectively.

Conclusion:

MDCT imaging offers a safe, accurate and noninvasive modality to differentiate between benign and malignant ovarian masses.

Imaging of benign adnexal masses: characteristic presentations on ultrasound, computed tomography, and magnetic resonance imaging

Adnexal masses are common in the general population. Although ovarian cancer is a significant cause of mortality, large screening studies demonstrate that the majority of adnexal masses are benign. These benign masses include physiologic cysts, paraovarian masses, and benign ovarian lesions. It is important that gynecologists and radiologists appreciate the appearance of these lesions on multiple imaging modalities, including ultrasound, computed tomography, and magnetic resonance imaging to avoid unnecessary intervention.

MRI, CT, and PET/CT for ovarian cancer detection and adnexal lesion characterization

OBJECTIVE

The purpose of this article is to describe the role of MR, CT, and PET/CT in the detection of ovarian cancer and the evaluation of adnexal lesions.

CONCLUSION

The goal of imaging in ovarian cancer detection is to expeditiously distinguish benign adnexal lesions from those requiring further pathologic evaluation for malignancy. For lesions indeterminate on ultrasound, MRI increases the specificity of imaging evaluation, thus decreasing benign resections. CT is useful in diagnosis and treatment planning of advanced cancer. Although (18)F-FDG-avid ovarian lesions in postmenopausal women are considered suspicious for malignancy, PET/CT is not recommended for primary cancer detection because of high false-positive rates.

Functional ovarian lesions in children and adolescents: when to remove them

STUDY OBJECTIVE

Functional ovarian lesions represent 45% of all pediatric adnexal abnormalities. Their surgical management, even if frequent, is not clear, especially in pediatric age.

MATERIALS AND METHODS

We retrospectively reviewed 22 pediatric patients surgically treated for functional ovarian lesions from 2000 to 2006. The following characteristics were analysed: age, size of the lesion, ultrasound (US) aspect and clinical presentation.

RESULTS

The average age was 16.1 years of age (range: 6 months-18 years). Of the 22 functional lesions, 12 (55%) were follicular cysts and 10 (45%) corpus luteum ones. The average size was 6.7 cm (range: 5.1-33 cm). US scan showed simple lesions in 10 cases (45%) and complex ones in 12 cases (55%). In 16 girls (72.8%) the presenting symptom was abdominal pain while 2 patients (9%) presented abdominal distention. In the other 4 patients (16.2%) the lesion was found accidentally during US examination.

CONCLUSION

In pediatric subjects, functional ovarian cysts rarely required surgical intervention, though no complications or disorder recurrence were reported. To preserve ovarian function, conservative surgery has to be performed whenever feasible.

Magnetic resonance imaging of cystic adnexal lesions during pregnancy

Management of cystic adnexal lesions diagnosed during pregnancy is a challenging issue for obstetricians. The range of treatment options changes from immediate surgery to close follow-up. This pictorial essay illustrates the magnetic resonance imaging findings of various cystic adnexal lesions in pregnant patients. Magnetic resonance imaging may help in better characterization of some of the cystic adnexal lesions diagnosed during pregnancy without exposing the fetus to ionizing radiation.